Not receiving messages

I was hoping someone could help me. I use U.S. Cellular and have my text messaging enabled. The phone number is entered in my user info areacode+number with no spaces and no hyphens, and I have selected US Cellular as my provider. I can receive messages when I go to uscc.com and enter a message. However, when I have tested receiving messages from LJ I get a page that says my message was sent successfully but I never get it.